Feed-water-control system



April 21, 1931- L. v. WARNER FEED WATER CONTROL SYSTEM Filed Oct. 15, 1928 Patented Apr. 21, 1931 UNITED STATES PATENT OFFICE LORING WARNER, OF CLEVELAND, OHIO, ASSIGNOR TO THE SWART\VOUT COMPANY, OF CLEVELAND, OHIO, A CORPORATION 03 OHIO FEED-WATER-CONTROL SYSTEM Application filed. October 15, 1928. Serial No. 312,584.

- l plication, Serial No. 187,419 filed Septem her 24th, 1926, and allowed July 26th, 1928, U. S. PatentNo. 1,702,375, wherein the feed water regulating valve, along with a differential valve for controlling the pressure drop across the feed water regulating valve, were both installed beyond the economizer and remote from the boiler. My invention constitutes an improvement over the Barrett construction, particularly in that I position the feed water regulating valve as near the boiler as practicable to eliminate lag due to line friction in feeding the boiler. Consistent with my arrangement, I also provide means to protect the economizer against 25 surges in feed water pressure and to control the pressure drop across the feed water regulating valve.

It is therefore among the objects of my invention to protect the economizer. against surges in feed water pressure; to eliminate lag between the feed water valve and the boiler drum by positioning the valve very close to the drum; to control the pressure drop across the feed water valve and to accomplish the foregoing objects with an installation which may be simple, rugged and durable. Among the specific objects of my invention is the construction of a valve actuable according to determinable differences in fluid pressure between points remote from the valve.

Other objects will appear from the following description of a preferred form of myinvention, reference being hadto the accompanying drawings.

The drawings constitute a more or less H a main feed water header in which feed water pressure is maintained in excess of the boiler pressure, and as is well known, under various operating conditions, rises and surges greatly in excess of normal boiler pressure. Leading from the header is a feed water line 1 which conducts feed water through an economizer E thence through a feed water regulating valve 2 adjacent the boiler to the boiler drum B.

The feed water regulator, including the valve 2, may be of a well known type and follow generally the disclosure of the Copley Patent No. 1,193,125 issued August 1, 1916. Briefly stated, the regulator comprises a pressure generator 3 mounted on the conduit 4 which conduit communicates with the steam and water spaces of the drum and spans the plane of the water level indicated along the line L. The pressure generator 3 comprises a closed chamber having expansible fluid which is gasified according to the heat content of the fluid in the conduit 4 so that the pressure exerted by the generator is a function of the variation in water level.

the pressure chamber 6 of the valve 2. A spring 7 normally tends to close the feed water valve 2, and the valve is opened as pressure is generated in the chamber 6 as the water level in the boiler tends to fall.

Mounted in the feed water line 1, between the header and the economizer, I position a valve 10 having a closure member 11 actuated through a stem 12. The stem 12 is engaged by a diaphragm 13 which diaphragm defines upper and lower chambers 14 and 15 respectively. The valve stem 12 terminates below a coil spring 16 as at 17. The strain on the coil spring may be varied by an adjusting screw 18. l A stufling box at 19 retains ne conduit 5 leads from the generator to t feed water valve on the side away from the boiler drum, as at 32. One of the functions the valve 10 is therefore, to throttle or control the flow of feed water so that the pressure drop between the point 32 and the boiler drum will be a constant amount which equals the pressure exertedby the spring 16 upon the valve stem 12. An additional function of the valve which follows from its operation, and by reason of its position ahead of the economizer, is to protect the economizer from surges or high feed water pressure.

Branching fronr'the conduit 31', I also provide a conduit 33 which'leads to the feed line or to the body of the valve 1O at the point 34, which is located between the valve 10 and the 'economizer. provide a hand operated closure valve 35 and in the'conduit 31 I provide a similar valve 36, thus if it be desired to control the pressure drop between the point 34 and the boiler, the valve 36 may be closed and the valve 35 open so that the whole drop'through the economizer and to the boiler may equal the strain in the spring 16. I contemplate that under certain conditions of operation, it may be advisable to open both the valves 35 and 36 or to merely crack one the ofvalves and to open wide the other of the'valves. It will be appreciated that the adjustmentbetween the valves 35 and 36 may be arranged to control the feeding characteristics within the wide range which may be selected for any glven installation and changed as operating conditions warrant.

In addition to the branch conduit 33, I provide another branchconduit 40 leading from the conduit 31 to the feed water lineat the point between the valve 10 and the economizer, as at 41, and in this conduit I place a relief valve 42. If the'valve 35 be closed so that the valve 10 ismaintaining a pressure drop'between the point 32 and the" boiler equal to the strain in the spring 16,'a-nd if under these conditions, an extraordinary surgein header pressure tends to raise the pressure in the economizer before the efiect is felt in thepoint' 32, then the relief valve is set to open at a stipulated amount above normal pressure which. directs the surge of high pressure in the chamber 15' to close the valve 10 and protect the economizer.

Whatever pressure In this conduit, I

In operationif the boiler be operating at 500 pounds pressure and normal rating, let

us presume that for the purpose of maintain ing a constant water level, that the spring 16 is compressed so that the drop between the point 32 and the boiler drum will be 50 pounds, thus the pressure at the point 32 is 550 pounds. I

Presuming that at normal rating the pressure drop through the economizer and the feed line between the valve 10 and) the point sure in the header Whichpass through the valve 10, the economizer will 'be protectedby the increasing pressure in thec'hamber 15, which will" tend to closethe valve 10. .As long'as the rating remains substantially con: stant, the drop across the feed, water valve will remain substantially constant.

If however, the rating varies greatly in the operation of the boiler, thefriction loss between the valve 10and the point 32 may be such that the drop across the feedwater valve will vary and consequently disturb the water levelf In this event, boththe valves 35 and 36 maybe opened or the valve 35 may be closed while the valve36 is opened, so that the change in drop between the valve 10 and the point 32 willnot effect the drop across the feed water valve. As pointed out above, if the valve 35 be closed, the economiz er is protected against surges by the increasing pressure at the point 32 tending to close the valve 10p As mentioned above, however, the re-' lief valve 42 may bedepended upon to take care of unusual and sudden rises in pressure which might injure the economizer before other than by the claims appended hereto.

I claim: I V

1. The combination of a boiler, a feed water line therefor, an economizer in said line, a feed water valve iii said li-ne positioned between the economizer and boiler and adj acent the boiler and. responsive to changes in thermal conditions in the" boiler, and, differential valvemeans in said feedwaterline positioned beyond the ec'on'omizer controlled by the and pressure drop between the boiler and a point L between said valves for protecting the economizer against surges in feed water pressure.

2. The combination of a boiler, a feed water line therefor, an economizer in said line, a feed water valve in said line positioned be tween the economizer and boiler and adjacent the boiler and responsive to changes in thermal conditions in the boiler, and differential valve means in said feed water line positioned beyond the economizer controlled by the fluid pressure drop across the feed water valve for protecting the economizer againstsurges in feed water pressure. V

3. The combination of a boiler, a feed water line therefor, an economizer in said line a feed water valve in said line adjacent the boiler, differential valve means positioned beyond the economizer actuable according to the fluid pressure drop across parts of the system between said valve means and said boiler.

4;. The combination of a boiler, a feed water line therefor, an economizer in said line, a feed water valve in said line adjacent the boiler, differential valve means positioned beyond the economizer actuable according to the fluid pressure drop across the feed water valve.

5. A boiler feed water system including a boiler, an economizer, a feed water line leading thereto, a feed water regulating valve in the line between the economizer and the boiler for regulating the flow of feed water according to boiler conditions, valve means positioned in the line beyond the feed water regulating valve actuated by opposed fluid pressures, means for establishing boiler drum pressure in said valve means and means for establishing a pressure in the valve means opposed to the drum pressure taken from points on opposite sides of the economizer between said valve means and said feed water regulating valve.

6. In a boiler feed water system including a boiler, a feed water line leading thereto, an economizer, a feed water regulating valve in theline adjacent the boiler for regulating the flow of feed water according to boiler conditions, and valve means positioned in the line beyond the economizer actuated by opposed fiuid pressures, means for establishing boiler drum pressure in said valve means and means for establishing a pressure in the valve means opposed to the drum pressure taken from points on opposite sides of the economizer between said valve means and said feed water regulating valve.

7. In a boiler feed water system including a boiler, a feed Water line, a feed water valve in said line, an economizer, the combination of a pressure actuated diiferential valve positioned beyond the economizer and in the feed water line, said differential valve being actuated by a diaphragm on opposite sides of which opposed fluid pressures are established,

means for establishing the boiler drum pressure on one side of said diaphragm, and means for establishing feed water line pressure taken between the economizer and said differential valve on the other side of said diaphragm.

8. In a boiler feed water system including a boiler, a feed water line, a feed water valve in said line, an economizer, the combination of a pressure actuated differential valve posi tioned beyond the economizer and in the feed water line, said differential valve being actuated by a diaphragm on opposite sides of which opposed fluid pressures are established, means for establishing the boiler drum pressure on one side of said diaphragm, means for establishing the pressure taken between the economizer and the boiler on the other side of said diaphragm, and means for establishing feed water line pressure taken between the economizer and said differential valve on the last namedside of said diaphr: gm.

9. A boiler feed water system including a boiler, a feed water line therefor, a feed water valve in said line, an economizer and a pressure actuated valve positioned ahead of said economizer, said pressure actuated valve having a pressure chamber divided by a diaphragm, an adjustable spring acting on one side of said diaphragm tending to open the valve, a conduit leading from the boiler to the same side of said diaphragm and a conduit leading from the chamber on the opposite side of said diaphragm to the feed water line between said feed water regulating valve and said economizer, and a branch of said last named conduit controlled by a relief valve connected to said feed water line ahead of said economizer.

10. A boiler feed water system including a boiler, a feed water line therefor, a feed water valve in said line, an economizer and a pressure actuated valve positioned ahead of said economizer, said pressure actuated valve having a pressure chamber divided by a diaphragm, a conduit leading from the boiler drum to one side of said diaphragm and a conduitfrom the chamber on the opposite side of said diaphragm and branching to the feed water line at a plurality of points between said valve and said feed water regulating valve, and valve means in the branches of said conduit whereby pressures may be taken from selected points along said feed water line and established in said chamber.

11. The combination of a boiler, a feed water line, an economizer, a feed water valve in said line positioned between the economizer and the boiler, and a differential pressure actuated valve in said line positioned ahead of the economizer, an operating connection to said differential valve from the boiler drum, a second operating connection from said differential valve to said feed line between the economizer and said feed valve and F a branch from said second connection to said feed line between said differential valve and "said. economizer.

with a second branch connection leading from said second connection to the feed line between the differential valve and the econo- 'mizer and a relief'valve in said second branch connection operable to permit the flow of fluidtherethrough when the pressure between the differential valve and the economizer exceeds a given amount.

15. The combination according to claim 12 with a second branch connection leading from said second connection to the feed line between the differential valve and the economizer and a relief Valve in said second branch connection operable to permit'the flow of fluid therethrough when the pressure between the difierential valve and the economizer exceeds a given amount 16. The combination of'a boiler, a feed water line therefor, an economizer in said line, a feed valve in said line between the economizer and the boiler and a pressure actuable valve positioned ahead of the econo mizer having a part movable in response to opposed fluid pressures, means for exerting a constant pressure to move said part, pressure chambers on opposite sides of said part each isolated from the body of said valve, a fluid connection between one of said chambers to the boiler and a fluid connection in the other of said chambers to the feed line at a point between the feed valve and the economizer.

17. The combination of a boiler, a feed water line, a feed valve in said line, and means for controlling the fluid pressure drop across said feed valve adapted to be spacedfrom said feed valve and operable in'response to changes in pressure across said feed valve comprising a valve having a body with seats, a closure member engageable with said 7 seats, a stem connected to said closure memsides: ofsaid part through the walls. of oneofwhich said valve stem passes, excess pressure means acting upon saidpart to move said valve stem and closure member, a fluid signature.

LORING V. WVARNER. 

